The threat of Hacker group "nightmare" was not prank. It was clearly proved on 10 AM (pick hour) whenTel Aviv Stock Exchange (TASE) and El Al’s respective websites goes offline. TASE's website was only partially functioning, while El Al’s website did not function at all. Following the attack, Israeli Bank ordered to block IP addresses from Saudi Arabia, Iran and Algeria, fearing hackers could penetrate databases of Israeli banks. Even before Israel Bank gave the order, Discount bank and Bank Leumi blocked international access altogether.The hack comes in the wake of a series of cyber attacks over the past two weeks, and only a day after Hamas called for harsher hacking attempts against Israeli websites.“The penetration into Israeli websites opens a new front for electronic resistance and war against the Israeli occupation,” said Hamas spokesperson Sami Abu Zuhri on Sunday during a news conference in the Gaza Strip. A TASE spokesperson stated that the trading system and the website are not connected, emphasizing that the trading system was in no way damaged by the hack.